A Series wiretap is a current-activated RF transmitter placed in series with one side of the telephone line. It transmits when the telephone circuit has been completed, and exchange current flows. By using the phone lineÃ­s voltage from the phone company, no power supply or batteries are required.
Series wiretaps can be connected in many places, on the phone line, a terminal block where your phone plugs into the wall, and even inside of the phone equipment. Wiretapping does require some practice if you are not familiar with the 2 or 4 wires that phone signals travel on. If you want a Series phone transmitter to wire tap a multi-line phone, you would place the series tap transmitter inside the actual phone equipment.
The Series Telephone Transmitter employs crystal controlled frequencies to ensure exceptional transmission stability. The Series Telephone Transmitter or Series Tap does not require batteries. The Series Transmitter derives its operating power from the telephone line power, and can function indefinitely.

Note: Unavailable in the UNITED STATES (WE WILL ONLY SHIP U.S. ORDERS TO AUTHORIZED MEMBERS OF UNITED STATES LAW ENFORCEMENT - PROOF REQUIRED FOR SHIPMENT)